Buildings have traditionally been designed to support their own weight plus that of expected inhabitants and furnishings. Buildings and other structures for supporting weight have long been expected to be very strong under vertical compression. Concrete is a favorite material for weight-bearing structures because it is inexpensive and has exceptional compressive strength.
In the mid-1900s, architects began to take lateral forces into account more than they had previously. Wind can exert strong lateral force on tall buildings and long bridges Smaller structures were still designed without much regard for strong lateral forces, though, until concern for earthquake resistance began growing in the 1970s in the United States, partly due to the massive Anchorage earthquake in 1964.
As understanding of the risk of earthquake increases, building codes require increasing resistance to lateral forces. Discovery of more earthquake faults all the time keeps increasing the area of inhabited land that is known to be at risk from earthquakes. Lateral forces on structures can also result from hurricanes, tornadoes, explosion, and impact.
Many buildings are still in use that were not built to withstand strong lateral forces. Some smaller structures, such as stadium seating and library shelves, have almost no built-in resistance to lateral forces. These could be toppled or collapsed by an earthquake and kill or injure people.
There is a need for a means to reinforce old structures so that they resist strong lateral force, such as could be caused by earthquake, storm, or explosion. Some present techniques for reinforcing structures require encapsulation of the structure in steel rods or panels, sprayed-on concrete, or resin-impregnated fiber panels. Other techniques require extensive excavation next to the structure or addition of external buttresses. These present techniques have disadvantages and are not applicable to all situations.
Encapsulation is generally undesirable in the case of an historical structure and is not feasible for all types of structures. There is frequently not room available for techniques that require excavation, external reinforcing members, or thickening of the structure. Many beautiful structures have been demolished or stand unused because no means could be found to make them safe enough. Other structures have been abandoned because the owner could not afford the high cost of reinforcement.
The anchor of the present invention is an inexpensive and effective way to reinforce many types of structure. The present invention can be installed in a small area with minimal disruption of the functioning of the structure. The invention is an efficient way to reinforce stadium seats, large shelves, or building elements including columns, walls, and beams.